In recent years all-purpose liquid detergents have become widely accepted for cleaning hard surfaces, e.g., painted woodwork and panels, tiled walls, wash bowls, bathtubs, linoleum or tile floors, washable wall paper, etc. Such all-purpose liquids comprise clear and opaque aqueous mixtures of water-soluble synthetic organic detergents and water-soluble detergent builder salts. In order to achieve comparable cleaning efficiency with granular or powdered all-purpose cleaning compositions, use of water-soluble inorganic phosphate builder salts was favored in the prior art all-purpose liquids. For example, such early phosphate-containing compositions are described in U.S. Pat. Nos. 2,560,839; 3,234,138; 3,350,319; and British Patent No. 1,223,739.
In view of the environmentalist""s efforts to reduce phosphate levels in ground water, improved all-purpose liquids containing reduced concentrations of inorganic phosphate builder salts or non-phosphate builder salts have appeared. A particularly useful self-opacified liquid of the latter type is described in U.S. Pat. No. 4,244,840.
However, these prior art all-purpose liquid detergents containing detergent builder salts or other equivalent tend to leave films, spots or streaks on cleaned unrinsed surfaces, particularly shiny surfaces. Thus, such liquids require thorough rinsing of the cleaned surfaces which is a time-consuming chore for the user.
In order to overcome the foregoing disadvantage of the prior art all-purpose liquid, U.S. Pat. No. 4,017,409 teaches that a mixture of paraffin sulfonate and a reduced concentration of inorganic phosphate builder salt should be employed. However, such compositions are not completely acceptable from an environmental point of view based upon the phosphate content. On the other hand, another alternative to achieving phosphate-free all-purpose liquids has been to use a major proportion of a mixture of anionic and nonionic detergents with minor amounts of glycol ether solvent and organic amine as shown in U.S. Pat. No. 3,935,130. Again, this approach has not been completely satisfactory and the high levels of organic detergents necessary to achieve cleaning cause foaming which, in turn, leads to the need for thorough rinsing which has been found to be undesirable to today""s consumers.
Another approach to formulating hard surfaced or all-purpose liquid detergent composition where product homogeneity and clarity are important considerations involves the formation of oil-in-water (o/w) microemulsions which contain one or more surface-active detergent compounds, a water-immiscible solvent (typically a hydrocarbon solvent), water and a xe2x80x9ccosurfactantxe2x80x9d compound which provides product stability. By definition, an o/w microemulsion is a spontaneously forming colloidal dispersion of xe2x80x9coilxe2x80x9d phase particles having a particle size in the range of 25 to 800 xc3x85 in a continuous aqueous phase.
In view of the extremely fine particle size of the dispersed oil phase particles, microemulsions are transparent to light and are clear and usually highly stable against phase separation.
Patent disclosures relating to use of grease-removal solvents in o/w microemulsions include, for example, European Patent Applications EP 0137615 and EP 0137616xe2x80x94Herbots et al; European Patent Application EP 0160762xe2x80x94Johnston et al; and U.S. Pat. No. 4,561,991xe2x80x94Herbots et al. Each of these patent disclosures also teaches using at least 5% by weight of grease-removal solvent.
It also is known from British Patent Application GB 2144763A to Herbots et al, published March 13, 1985, that magnesium salts enhance grease-removal performance of organic grease-removal solvents, such as the terpenes, in o/w microemulsion liquid detergent compositions. The compositions of this invention described by Herbots et al. require at least 5% of the mixture of grease-removal solvent and magnesium salt and preferably at least 5% of solvent (which may be a mixture of water-immiscible non-polar solvent with a sparingly soluble slightly polar solvent) and at least 0.1% magnesium salt.
However, since the amount of water immiscible and sparingly soluble components which can be present in an o/w microemulsion, with low total active ingredients without impairing the stability of the microemulsion is rather limited (for example, up to 18% by weight of the aqueous phase), the presence of such high quantities of grease-removal solvent tend to reduce the total amount of greasy or oily soils which can be taken up by and into the microemulsion without causing phase separation.
U.S. Pat. No. 6,037,319 teaches a water soluble sachet containing a cleaning composition containing an alcohol and hexylene glycol.
U.S. Pat. No. 5,783,541 teaches a dishwashing composition disposed in a water soluble film, wherein the water soluble film is coated with a water dissolvable glue.
UK Patent Application GB2355269A teaches a pouched liquid cleaning composition containing an alkoxylated amine.
U.S. Pat. No. 6,136,776 teaches a pouched liquid cleaning composition containing a quaternary ammonium compound.
U.S. Pat. No. 6,037,319 teaches a pouched liquid cleaning composition containing an alkylene glycol.
The present invention provides a cleaning system comprising a water soluble sachet containing a powdered cleaning composition having excellent high foaming properties and excellent grease cutting property which, when diluted in a bucket, is suitable for cleaning hard surfaces such as plastic, vitreous and metal surfaces having a shiny finish, oil stained floors, automotive engines and other engines. More particularly, the improved cleaning compositions, with excellent high foaming properties and excellent grease cutting property exhibit good grease soil removal properties due to the improved interfacial tensions, when used diluted and leave the cleaned surfaces shiny without the need of or requiring only minimal additional rinsing or wiping. The latter characteristic is evidenced by little or no visible residues on the unrinsed cleaned surfaces and, accordingly, overcomes one of the disadvantages of prior art products.
In one aspect, the invention generally provides a stable, water soluble sachet made of a water soluble thermoplastic wherein the sachet contains a powdered cleaning composition which comprises approximately by weight:(a) 10% to 20% of an anionic surfactant;(b)0.1% to 5% of a nonionic surfactant;(c)5% to 15% of a salt;(d)15% to 30% of an alpha hydroxy aliphatic acid such as citric acid;(e)0.1% to 1.5% of a perfume;(f)20% to 40% of an alkali metal bicarbonate; and(g)1% to 15% of a bleach compound, wherein the composition does not contain more than 7 wt. %, more preferably 5 wt. % of water.
The present invention relates to a water soluble sachet containing a unit dose of a powdered cleaning composition wherein the water soluble sachet is formed from a single layer of film water soluble thermo plastic such as a polyvinyl alcohol, wherein the inner layer of the film is in contact with the cleaning composition and the external layer of the film does not have a water soluble glue disposed thereon.
The powdered cleaning composition contained in the water soluble sachet comprises approximately by weight:(a)10% to 20%, more preferably 12% to 18% of an anionic surfactant;(b)0.1% to 5%, more preferably 0.2% to 3% of a nonionic surfactant; (c)5% to 15%, more preferably 7% to 13% of a multivalent salt;(d)15% to 30%, more preferably 18% to 27% of an alpha hydroxy aliphatic acid such as citric acid;(e)0.1% to 1.5%, more preferably 0.3% to 1.3% of a perfume;(f)20% to 40%, more preferably 25% to 35% of an alkali metal bicarbonate; and(g)1% to 15%, more preferably 4% to 14% of a bleach compound.
As used herein and in the appended claims the term xe2x80x9cperfumexe2x80x9d is used in its ordinary sense to refer to and include any non-water soluble fragrant substance or mixture of substances including natural (i.e., obtained by extraction of flower, herb, blossom or plant), artificial (i.e., mixture of natural oils or oil constituents) and synthetically produced substance) odoriferous substances. Typically, perfumes are complex mixtures of blends of various organic compounds such as alcohols, aldehydes, ethers, aromatic compounds and-varying amounts of essential oils (e.g., terpenes) such as from 0% to 80%, usually from 10% to 70% by weight, the essential oils themselves being volatile odoriferous compounds and also serving to dissolve the other components of the perfume.
In the present invention the precise composition of the perfume is of no particular consequence to cleaning performance so long as it meets the criteria of water immiscibility and having a pleasing odor. Naturally, of course, especially for cleaning compositions intended for use in the home, the perfume, as well as all other ingredients, should be cosmetically acceptable, i.e., non-toxic, hypoallergenic, etc. The at least one nonionic surfactant used in the instant cleaning composition is selected from the group of an aliphatic ethoxylated nonionic surfactant and an aliphatic ethoxylated/propoxylated nonionic surfactant and mixtures thereof.
The water soluble aliphatic ethoxylated nonionic surfactants utilized in this invention are commercially well known and include the primary aliphatic alcohol ethoxylates and secondary aliphatic alcohol ethoxylates. The length of the polyethenoxy chain can be adjusted to achieve the desired balance between the hydrophobic and hydrophilic elements.
The nonionic surfactant class includes the condensation products of a higher alcohol (e.g., an alkanol containing about 8 to 16 carbon atoms in a straight or branched chain configuration) condensed with about 4 to 20 moles of ethylene oxide, for example, lauryl or myristyl alcohol condensed with about 16 moles of ethylene oxide (EO), tridecanol condensed with about 6to 15 moles of EO, myristyl alcohol condensed with about 10 moles of EO per mole of myristyl alcohol, the coridensation product of EO with a cut of coconut fatty alcohol containing a mixture of fatty alcohols with alkyl chains varying from 10 to about 14 carbon atoms in length and wherein the condensate contains either about 6 moles of EO per mole of total alcohol or about 9 moles of EO per mole of alcohol and tallow alcohol ethoxylates containing 6 EO to 11 EO per mole of alcohol.
A preferred group of the foregoing nonionic surfactants are the Neodol ethoxylates (Shell Co.), which are higher aliphatic, primary alcohol containing about 9-15 carbon atoms, such as C9-C11 alkanol condensed with 4 to 10 moles of ethylene oxide (Neodol 91-8 or Neodol 91-5), C12-13 alkanol condensed with 6.5 moles ethylene oxide (Neodol 23-6.5), C12-15 alkanol condensed with 12 moles ethylene oxide (Neodol 25-12), C14-15 alkanol condensed with 13 moles ethylene oxide (Neodol 45-13), and the like. Such ethoxamers have an HLB (hydrophobic lipophilic balance) value of about 8 to 15 and give good O/W emulsification, whereas ethoxamers with HLB values below 7 contain less than 4 ethyleneoxide groups and tend to be poor emulsifiers and poor detergents.
Additional satisfactory water soluble alcohol ethylene oxide condensates are the condensation products of a secondary aliphatic alcohol containing 8 to 18 carbon atoms in a straight or branched chain configuration condensed with 5 to 30 moles of ethylene oxide. Examples of commercially available nonionic detergents of the foregoing type are C11-C15 secondary alkanol condensed with either 9 EO (Tergitol 15-S-9) or 12 EO (Tergitol 15-S-12) marketed by Union Carbide.
One of the water soluble nonionic surfactants which can be utilized in this invention are an aliphatic ethoxylated/propoxylated nonionic surfactants which are depicted by the formula: 
wherein R is a branched chain alkyl group having about 10 to about 16 carbon atoms, preferably an isotridecyl group and x and y are independently numbered from 1 to 20. A preferred ethoxylated/propoxylated nonionic surfactant is Plurafac(copyright) 300 manufactured by BASF.
Regarding the anionic surfactant present in the powdered cleaning compositions any of the conventionally used water-soluble anionic surfactants or mixtures of said anionic surfactants and anionic surfactants can be used in this invention. As used herein the term xe2x80x9canionic surfactantxe2x80x9d is intended to refer to the class of anionic and mixed anionic-nonionic detergents providing detersive action.
Suitable water-soluble non-soap, anionic surfactants include those surface-active or detergent compounds which contain an organic hydrophobic group containing generally 8 to 26 carbon atoms and preferably 10 to 18 carbon atoms in their molecular structure and at least one water-solubilizing group selected from the group of sulfonate, sulfate and carboxylate so as to form a water-soluble detergernt. Usually, the hydrophobic group will include or comprise a C8-C22 alkyl, alkyl or acyl group. Such surfactants are employed in the form of water-soluble salts and the salt-forming cation usually is selected from the group consisting of sodium, potassium, ammonium, magnesium and mono-, di- or tri-C2-C3 alkanolammonium, with the sodium, magnesium and ammonium cations again being preferred.
Examples of suitable sulfonated anionic surfactants are the well known higher alkyl mononuclear aromatic sulfonates such as the higher alkyl benzene sulfonates containing from 10 to 16 carbon atoms in the higher alkyl group in a straight or branched chain, C8-C15 alkyl toluene sulfonates and C8-C15 alkyl phenol sulfonates.
A preferred sulfonate is linear alkyl benzene sulfonate having a high content of 3-(or higher) phenyl isomers and a correspondingly low content (well below 50%) of 2-(or lower) phenyl isomers, that is, wherein the benzene ring is preferably attached in large part at the 3 or higher (for example, 4, 5, 6 or 7) position of the alkyl group and the content of the isomers in which the benzene ring is attached in the 2 or 1 position is correspondingly low. Particularly preferred materials are set forth in U.S. Pat. No. 3,320,174.
Other suitable anionic surfactants are the olefin sulfonates, including long-chain alkene sulfonates, long-chain hydroxyalkane sulfonates or mixtures of alkene sulfonates and hydroxyalkane sulfonates. These olefin sulfonate detergents may be prepared in a known manner by the reaction of sulfur trioxide (SO3) with long-chain olefins containing 8 to 25, preferably 12 to 21 carbon atoms and having the formula RCH=CHR1 where R is a higher alkyl group of 6 to 23 carbons and R1 is an alkyl group of 1 to 17 carbons or hydrogen to form a mixture of sultones and alkene sulfonic acids which is then treated to convert the sultones to sulfonates. Preferred olefin sulfonates contain from 14 to 16 carbon atoms in the R alkyl group and are obtained by sulfonating an a-olefin.
Other examples of suitable anionic sulfonate surfactants are the paraffin sulfonates containing 10 to 20, preferably 13 to 17, carbon atoms. Primary paraffin sulfonates are made by reacting long-chain alpha olefins and bisulfites and paraffin sulfonates having the sulfonate group distributed along the paraffin chain are shown in U.S. Pat. Nos. 2,503,280; 2,507,088; 3,260,744; 3,372,188; and German Patent 735,096.
Examples of satisfactory anionic sulfate surfactants are the C8-C18 alkyl sulfate salts and the C8-C18 alkyl sulfate salts and the C8-C18 alkyl ether polyethenoxy sulfate salts having the formula R(OC2H4)n OSO3M wherein n is 1 to 12, preferably 1 to 5, and M is a solubilizing cation selected from the group consisting of sodium, potassium, ammonium, magnesium and mono-, di- and triethanol ammonium ions. The alkyl sulfates may be obtained by sulfating the alcohols obtained by reducing glycerides of coconut oil or tallow or mixtures thereof and neutralizing the resultant product.
On the other hand, the alkyl ether polyethenoxy sulfates are obtained by sulfating the condensation product of ethylene oxide with a C8-C18 alkanol and neutralizing the resultant product. The alkyl sulfates may be obtained by sulfating the alcohols obtained by reducing glycerides of coconut oil or tallow or mixtures thereof and neutralizing the resultant product. On the other hand, the alkyl ether polyethenoxy sulfates are obtained by sulfating the condensation product of ethylene oxide with a C8-C18 alkanol and neutralizing the resultant product. The alkyl ether polyethenoxy sulfates differ from one another in the number of moles of ethylene oxide reacted with one mole of alkanol. Preferred alkyl sulfates and preferred alkyl ether polyethenoxy sulfates contain 10 to 16 carbon atoms in the alkyl group.
The C8-C12 alkylphenyl ether polyethenoxy sulfates containing from 2 to 6 moles of ethylene oxide in the molecule also are suitable for use in the inventive compositions. These surfactants can be prepared by reacting an alkyl phenol with 2 to 6 moles of ethylene oxide and sulfating and neutralizing the resultant ethoxylated alkylphenol.
Other suitable anionic detergents are the C9-C15 alkyl ether polyethenoxyl carboxylates having the structural formula R(OC2H4)nOX COOH wherein n is a number from 4 to 12, preferably 5 to 10 and X is selected from the group consisting of CH2, C (O)R1 and 
wherein R1 is a C1-C3 alkylene group. Preferred compounds include C9-C11 alkyl ether polyethenoxy (7-9) C(O) CH2CH2COOH, C13-C15 alkyl ether polyethenoxy (7-9) 
and C10-C12 alkyl ether polyethenoxy (5-7) CH2COOH. These compounds may be prepared by condensing ethylene oxide with appropriate alkanol and reacting this reaction product with chloracetic acid to make the ether carboxylic acids as shown in U.S. Pat. No. 3,741,911 or with succinic anhydride or phtalic anhydride.
Obviously, these anionic detergents will be present either in acid form or salt form depending upon the pH of the final composition, with the salt forming cation being the same as for the other anionic detergents.
Of the foregoing non-soap anionic surfactants, the preferred surfactants are the C9-C15 linear alkylbenzene sulfonates and the C13-C17 paraffin or alkane sulfonates. Particularly, preferred compounds are sodium C10-C13 alkylbenzene sulfonate and sodium C13-C17 alkane sulfonate.
The multivalent salt is an inorganic or organic salt of oxide of a multivalent metal cation, particularly magnesium with a valence of +2. The metal salt or oxide provides several benefits including improved cleaning performance in dilute usage, particularly in soft water areas. Magnesium sulfate, either anhydrous or hydrated (e.g., heptahydrate), is especially preferred as the magnesium salt. Good results also have been obtained with magnesium oxide, magnesium chloride, magnesium acetate, magnesium propionate and magnesium hydroxide. These magnesium salts can be used with formulations at neutral or acidic pH since magnesium hydroxide will not precipitate at these pH levels. Although magnesium is the preferred multivalent metal from which the salts (inclusive of the oxide and hydroxide) are formed, other polyvalent metal ions also can be used provided that their salts are nontoxic.
The bleach which is used in the instant composition is selected from the group of chlorine bleach such as sodium dichloroisocyanurate, clichloro-dimethyl hydantoin and chlorinated TSP and mixtures thereof peroxygen bleach such as potassium monopersulfate.
The powdered cleaning composition of this invention may, if desired, also contain other components either to provide additional effect or to make the product more attractive to the consumer. The following are mentioned by way of example: Colors or dyes in amounts up to 0.5% by weight; bactericides in amounts up to 1% by weight; preservatives or antioxidizing agents, such as formalin, 5-bromo-5-nitro-dioxan-1,3; 5-chloro-2-methyl-4-isothaliazolin-3-one, 2,6-di-tert.butyl-p-cresol, etc., in amounts up to 2% by weight.
In final form, the cleaning compositions which contain less than 7 wt. %, more preferably less than 5 wt. % and most preferably less than 2 wt. % of water exhibit stability at reduced and increased temperatures. Such compositions exhibit a pH, at 1% solution, in the acid or neutral range depending on intended end use.
The compositions are easily prepared simply by combining all the ingredients in a suitable vessel or container. The order of mixing the ingredients is not particularly important and generally the various ingredients can be added sequentially.
The water soluble container which can be in the form of a sachet, a blow molded capsule or other blow molded shapes, an injected molded ampoule or other injection molded shapes, or rotationally molded spheres or capsules are formed from a water soluble thermoplastic resin. Water soluble plastics which may be considered for forming the container include low molecular weight and/or chemically modified polylactides; such polymers have been produced by Chronopol, Inc. and sold under the Heplon trademark. Also included in the water soluble polymer family are melt processable poly(vinyl) alcohol resins (PVA); such resins are produced by Texas Polymer Services, Inc., tradenamed Vinex, and are produced under license from Air Products and Chemicals, Inc. and Monosol film produced by Chris Craft Film. Other suitable resins include poly (ethylene oxide) and cellulose derived water soluble carbohydrates. The former are produced by Union Carbide, Inc. and sold under the tradename Polyox; the latter are produced by Dow Chemical, Inc. and sold under the Methocel trademark. Typically, the cellulose derived water soluble polymers are not readily melt processable. The preferred water soluble thermoplastic resin for this application is Chris Craft Film. Any number or combination of PVA resins can be used. The preferred grade, considering resin processability, container durability, water solubility characteristics, and commercial viability is Monosol film having a weight average molecular weight range of about 55,000 to 65,000 and a number average molecular weight range of about 27,000 to 33,000.
The sachet may be formed from poly(vinyl) alcohol film. The pelletized, pre-dried, melt processable polyvinyl alcohol (PVA) resin, is feed to a film extruder. The feed material may also contain pre-dried color concentrate which uses a PVA carrier resin. Other additives, similarly prepared, such as antioxidants, UV stabilizers, anti-blocking additives, etc. may also be added to the extruder. The resin and concentrate are melt blended in the extruder. The extruder die may consist of a circular die for producing blown film or a coat hanger die for producing cast film. Circular dies may have rotating die lips and/or mandrels to modify visual appearance and/or properties.
Typical film properties are:1. Tensile strength (125 mil, break, 50% RH)=4,700 to 5,700 psi; 2. Tensile modulus (125 mil 50% RH)=47,000 to 243,000 psi; preferred range is 740,000 to 150,000 psi, 3. Tear resistance (mean) (ASTM-D-199gm/ml)=900-15004. Impact strength (mean) (ASTM-D-1709, gm)=600-1,000; 5. 100% Elongation (mean) (ASTM-D-882, psi)=300-600; 6. Oxygen transmission (1.5 mil, 0% RH, 1 atm)=0.0350 to 0.450 cc/100 sq. in./24 h; 7. Oxygen transmission (1.5 mil, 50% RH, 1 atm)=1.20 to 1.50 cc/100 sq. in./24 h; 8. 100% modulus (mean) (ASTM-D-882, psi)=1000-3000; 9. Solubility (sec) (MSTM-205,75xc2x0 F.) disintegration=1-15; dissolution=10-30 Typical resin properties are: 1. Glass Transition Temperature (xc2x0C.)=28 to 38; preferred is 28 to 33; 2. Weight Average Molecular Weight (Mw)=15,000 to 95,000; preferred is 55,000-65,000; 3. Number Average Molecular Weight (Mn)=7,500 to 60,000; preferred is 27,000 to 33,000. Preferred poly(vinyl) alcohol film is formed from Monosol 7030 or Monosol 8630. The extruded film is slit to the appropriate width and wound on cores. Each core holds one reel of film. The reels of slit film are fed to either a vertical form, fill, seal machine (VFFS) or a horizontal form, fill, seal machine (HFFS). The Form, Fill, Seal machine (FFS) makes the appropriate sachet shape (cylinder, square, pillow, oval, etc.) from the film and seals the edges longitudinally (machine direction seal). The FFS machine also makes an end seal (transverse direction seal) and fills the appropriate volume of non-aqueous liquid above the initial transverse seal. The FFS machine then applies another end seal. The liquid is contained in the volume between the two end seals.
Blow molded capsules are formed from the poly(vinyl) alcohol resin having a molecular weight of about 50,000 to about 70,000 and a glass transition temperature of about 28 to 33xc2x0 C. Pelletized resin and concentrate(s) are feed into an extruder. The extruder into which they are fed has a circular, oval, square or rectangular die and an appropriate mandrel. The molten polymer mass exits the die and assumes the shape of the die/mandrel combination. Air is blown into the interior volume of the extrudate (parison) while the extrudate contacts a pair of split molds. The molds control the final shape of the package. While in the mold, the package is filled with the appropriate volume of liquid. The mold quenches the plastic. The powder is contained within the interior volume of the blow molded package.
An injection molded ampoule or capsule is formed from the poly(vinyl) alcohol resin having a molecular weight of about 50,000 to about 70,000 and a glass transition temperature of about 28 to 38xc2x0 C. Pelletized resin and concentrate(s) are fed to the throat of an reciprocating screw, injection molding machine. The rotation of the screw pushes the pelletized mass forward while the increasing diameter of the screw compresses the pellets and forces them to contact the machine""s heated barrel. The combination of heat, conducted to the pellets by the barrel and frictional heat, generated by the contact of the pellets with the rotating screw, melts the pellets as they are pushed forward. The molten polymer mass collects in front of the screw as the screw rotates and begins to retract to the rear of the machine. At the appropriate time, the screw moves forward forcing the melt through the nozzle at the tip of the machine and into a mold or hot runner system which feeds several molds. The molds control the shape of the finished package. The package may be filled with liquid either while in the mold or after ejection from the mold. The filling port of the package is heat sealed after filling is completed. This process may be conducted either in-line or off-line.
A rotationally molded sphere or capsule is formed from the poly(vinyl) alcohol resin having a molecular weight of about 50,000 to about 70,6000 and a glass transition temperature of about 28 to 38xc2x0 C. Pelletized resin and concentrate are pulverized to an appropriate mesh size, typically 35 mesh. A specific weight of the pulverized resin is fed to a cold mold having the desired shape and volume. The mold is sealed and heated while simultaneously rotating in three directions. The powder melts and coats the entire inside surface of the mold. While continuously rotating, the mold is cooled so that the resin solidifies into a shape which replicates the size and texture of the mold. After rejection of the finished package, the liquid is injected into the hollow package using a heated needle or probe after filling, the injection port of the package is heat sealed.